Since the federal government now controls cannabis based on the total tetrahydrocannabinol (THC) content of 0.3% by dry weight, law enforcement, particularly in states in which cannabis is still controlled, faces many new challenges regarding the potential seizure of cannabis. No longer is the traditional Duquenois-Levine color reaction test utilized by law enforcement for many years able to distinguish between legal versus illegal forms of cannabis; both federally legal and illegal cannabis contain cannabinoids, which produce positive responses for this presumptive test. Law enforcement officers often need a quick answer when it comes to deciding whether or not to seize potential cannabis without the fear of a potential lawsuit. They often do not have the time to send a sample to an analytical lab and wait weeks for the results. This study evaluated the C-Vue Liquid Chromatograph (LC) as a simple, robust, affordable presumptive tool that, within less than an hour, allows officers to determine whether the sample is most likely legal (hemp) or illegal cannabis (marijuana) based on the 0.3% THC threshold. When this data was compared against a validated research-grade LC, using a set of 50 cannabis samples from different sources, the C-Vue correctly predicted whether the THC concentration was above or below the 0.3 wt. % threshold in 48 out of 50 samples, suggesting that the C-Vue may be useful as a presumptive tool.